A recent accident in the Gulf of Mexico revealed the difficulty of controlling and stopping an erupting underwater oil well, when a confinement system cannot contain the pressure from the well. Furthermore, in such a situation, capturing and bringing up the fluid is pointless without adequate support on the surface, while the surface means necessary to treat an oil effluent are difficult to mobilize quickly on-site.
U.S. Pat. No. 7,448,404 describes an underwater hydrocarbon storage installation including a plurality of tanks. However, this installation is not adapted for intervening on an accidental hydrocarbon leak. In fact, it involves a heavy rigid structure, difficult to deploy quickly and requiring dedicated vessels, which are generally not available on the site of an offshore oil accident. Furthermore, all of the tanks are connected in parallel to a supply pipe by bleeds provided with valves, and said bleeds risk becoming plugged quickly due to the formation of hydrates resulting from cooling of the oil-gas-water mixture coming from the erupting well.